Apparatus and method for producing brushware by injection molding

ABSTRACT

An apparatus and method for producing brushes. The bristle bundles are loaded into a magazine which includes part of a cavity for an injection mold. The magazine is mated with the remainder of the injection mold and the brush handle injection molded around the bristles. The bristles may be profiled, trimmed, end-rounded, fused, or otherwise processed before the handle is injection molded. In addition, the handle of the brush may be formed in two injection molding steps of two different materials. An apparatus is taught which enables the brush to be produced, optionally ornamented, and packaged on a single machine.

[0001] This application is a divisional application of and claims thepriority of U.S. patent application Ser. No. 09/494,946, filed Feb. 1,2000, the entire contents of which are incorporated by reference herein.

FIELD OF THE INVENTION

[0002] This invention is related to methods for producing brushware byinjection molding, specifically methods of producing brushware byin-mold bristling techniques.

BACKGROUND OF THE INVENTION

[0003] The variety of brands, designs, and styles of toothbrushesavailable in the United States today is truly staggering. Brushes areavailable in sizes and styles appropriate for babies, adults, dentures,sensitive gums, and other specialized needs. Brushes can be had in everycolor of the rainbow and decorated with logos ranging from mermaids andcartoon characters to trade names of various kinds. Most brushes areproduced via a two part technique. The handles are produced by injectionmolding, and the bristles are later inserted into a head portion of thehandle. One common technique for inserting the bristles into the brushesis to staple them. Bristles are folded around a metal staple which ispushed into pre-molded holes in the brush. The staple cuts its way intothe brush handle, which holds it and the bristles securely. However,rough use can easily remove the bristles from the handle, leading toshedding, or, in a worst case scenario, release of the metal stapleinside the mouth.

[0004] Techniques wherein the bristles are fused with the handles can beused to produce brushes where the bristles are much harder to removefrom the brush. Either the bristles or the brush head, or both, areheated, and the bristles are inserted into holes in the handle, wherethey are retained by the cooling plastic. Exemplary techniques for brushproduction by fusion, such as those disclosed in U.S. Pat. Nos.4,609,228 and 4,646,381, produce brushes with high bristle retentionstrength but retain the economic disadvantage that the brush is producedin a two-part process on two different machines. That is, the handlesare still produced on a different machine than the one on which thebristles are inserted into the handle. It is thus desirable to produce atoothbrush using techniques which minimize the apparatus used, andconsequently, the amount of time and number of personnel required toproduce the brushes.

[0005] In-mold bristling processes, wherein the handle of the brush isinjection molded around the bristles, have been used to produce avariety of different brushes. For example, U.S. Pat. No. 4,635,313 (the'313 patent) to Fassler, describes an in-mold bristling process whereinthe ends of the bristles are fused prior to the injection molding of thehandle. The illustrative drawing on the front page of the patent shows anail brush; however, the technique can also be used to producetoothbrushes. One concern in the production of brushes by this techniqueis the penetration (“flash”) of injection molded material through thebristle bundles into the face of the brush. This is not only unsightlybut unhygienic because the excess material provides an excellent hidingplace for bacteria and mold. To prevent this, the '313 patent describesa method of sealing the opening of the injection mold through which thebristles enter the mold with a melted fuse at the end of the bristlebundles. U.S. Pat. No. 5,045,267 (the '267 patent) to Weihrauchdiscloses a variation of the in-mold bristling technique described inthe '313 patent. However, in the '267 patent, the fused ends of thebristle bundles are pulled against sleeves projecting from the end ofthe channels which lead into the mold. The tensile force holding thefuse against the sleeve further discourages injection molded materialfrom penetrating the bristle bundles.

[0006] U.S. Pat. No. 5,143,424 to Boucherie also describes an in-moldbristling process. Bristles are loaded into one end of a two-endedmagazine while, at the other end, the handle material is simultaneouslyinjection molded into a previously loaded second end of the magazine.Each of the two ends of the magazine can hold the bristles for a singlebrush and mate with an injection mold to complete a mold cavity intowhich the handle is injection molded.

[0007] U.S. Pat. No. 5,823,633 to Weihrauch describes an in-moldbristling process similar to that described by the '267 patent. However,in this invention, the fuseballs are not brought into sealing contactwith the sleeve. Instead, they are maintained at a finite distance,between 0.1 mm and 2.0 mm, from the opening of the channel, allowing airto escape from the mold cavity through the channel. The gap increasesthe depth of the fuses within the handle, reinforcing the length ofbristle bundle material immediately adjacent to the fuse and increasingthe force required to remove the bristle bundles from the brush handle.However, this technique also allows injection molded material topenetrate the bristle bundle and flash over the head of the brush.

[0008] U.S. Pat. No. 5,458,400 to Meyer and U.S. Pat. No. 5,474,366 toStrutt, et al., describe techniques wherein a first section of thebrush, including a portion of the head and at least part of the handleis injection molded before the bristles are inserted into the mold. Thebristle bundles are inserted into holes in the first brush section,after which the rest of the brush is injection molded.

[0009] U.S. Pat. No. 5,609,890 to Boucherie describes an in-moldbristling process wherein the handle comprises two materials instead ofa single injection molded material. The invention utilizes a moldingmachine which comprises at least two injection molding stations and atuft feeding station. At the feeding station, the bristles are fed intoa magazine, following which the ends of the bristles are fused. Themagazine, which includes part of a mold cavity, is mated with the restof an injection mold, completing the mold cavity. The first section ofthe brush, including the head, is injection molded, following which themagazine, still carrying the first injection molded section of thebrush, is transferred to a second injection mold, whereat the remainderof the brush is injection molded.

SUMMARY OF THE INVENTION

[0010] In one aspect, the invention is a method for manufacturingbrushes. The method includes the steps of inserting a plurality ofbristle bundles into a first mold cavity in a magazine, manipulating atleast one end of the bristle bundles, mating the first mold cavityportion with a second injection mold cavity portion in an injectionmold, and injection molding at least a portion of a brush handle. Thefirst and second cavity portions define the shape of the portion of thebrush handle. The bristles may be inserted into the magazine from anendless supply or a supply of pre-cut bristles.

[0011] Manipulating may comprise adjusting the relative heights of thebristle bundles with respect to one another before the first part of thebrush handle is injection molded. Within the individual bristle bundles,the relative heights of a portion of the bristles may also be adjustedwith respect to each other at this time. A non-use side of the bristlebundles may be trimmed to produce a level plane, and a portion of thebristle bundle may be end-rounded before or following the step ofinjection molding. Following the initial adjusting step, the relativeheight of the bristle bundles with respect to one another may beinverted in a further adjusting step. Alternatively, manipulating mayinclude fusing a non-use end of each bristle bundle to form a regionhaving a greater diameter than that of the remainder of the bristlebundle. The fusion may be accomplished thermally or chemically and maybe followed by pressing the fused ends against a portion of the firstmold cavity portion. Thermal fusion may be accomplished by a contactheater, a non-contact heater, or hot air. If the bristles are fusedthermally, they may be partially flattened while the fused ends arestill warm. A portion of the brush handle may comprise polypropylene,cellulose propionate acetate, polyethylene terephthalate, or athermoplastic polymer.

[0012] The process may further comprise removing the completed portionof the brush handle from the second mold cavity portion, mating themagazine and the portion of the brush handle with a subsequent moldcavity portion, and injection molding an additional portion of the brushhandle. The completed portion of the brush handle and the subsequentmold cavity portion define the shape of the additional portion of thebrush handle. The additional portion may comprise a thermoplasticelastomer, polypropylene, cellulose propionate acetate, polyethyleneterephthalate, or a thermoplastic polymer. The completed portion of thebrush handle may be at least partially supported by the bristle bundleswhen it is carried by the magazine to the subsequent mold cavityportion, but not all the bristle bundles need be retained in thecompleted portion of the brush.

[0013] The magazine may be arranged and constructed to hold bristlebundles corresponding to a plurality of brushes such that the pluralityof brushes can be produced simultaneously. For example, the magazine maybe arranged and constructed to hold bristle bundles corresponding tofour brushes simultaneously. All of the brushes need not be the samecolor. The process may further comprise packaging, ornamenting, orlabeling the completed brush. Ornamenting may include hot-stamping,stamping a decoration, or applying a label. An insert may be placed intothe magazine to be incorporated into the completed brush. The insert maybe a metal shank or a plastic insert.

[0014] In another aspect, the invention is a magazine for conveyingbristle bundles along a brush making apparatus. The magazine includes amold face, a mold cavity portion disposed in the mold face having theshape of part of a head of the brush, a back side, a clamping platedisposed between the mold face and the back side, and a plurality ofchannels extending through the magazine into the mold cavity for holdingbristle bundles in a configuration corresponding to the desiredarrangement of a set of bristle bundles in a brush. The magazine mayhold sets of bristle bundles for a plurality of brushes and may bearranged and constructed to clamp and release the set of bristles foreach brush independently. For example, the magazine may be arranged andconstructed to hold at least four sets of bristle bundles. Each channelmay include an opening into the mold cavity portion with a slottedsleeve.

[0015] The magazine may further include a detachable trim plate incooperation with the mold cavity portion. The trim plate includeschannels which coincide with the channels through the magazine. Asurface of the trim plate may project above the mold face or be flushwith the mold face when the plate is in cooperation with the mold cavityportion. When the magazine is seated in an injection molding apparatus,the mold cavity portion of the magazine may cooperate with the moldcavity portion of the apparatus to define a mold cavity having the shapeof a portion of the brush. The magazine may further comprise a cut platemounted on the back side of the magazine with channels coinciding withthe channels through the magazine. A portion of the channels may beskewed with respect to one another or lie in intersecting planes.

[0016] In another aspect, the invention is a method for processingbristles for a brush. The method comprises holding the bristles inbundles in a magazine, adjusting the relative height of at least aportion of the bristle bundles with respect to one another, trimmingnon-use ends of at least a portion of the bristle bundles to produce alevel plane, heating the non-use ends of the bristle bundles to melt theends of the bristles, and end-rounding use-ends of the bristle bundles.The step of adjusting may be performed with pins which approach bothends of the bristle bundles. Alternatively, this step of adjusting maycomprise providing a plate in cooperation with a side of the magazinesuch that the plate includes holes in an arrangement corresponding to aconfiguration of the bristles in the magazine such that each hole endsin a surface corresponding to a desired arrangement of bristle strandsor the inverse of the desired arrangements of the bristle strands, andpressing an end of the bristle bundles against the surface in the holewith a pressurized fluid. This step of adjusting may further includeadjusting the relative heights of at least a portion of the bristleswithin the bundles with respect to one another.

[0017] After the step of heating and melting the non-use ends of thebristle bundles, the melted portion of the bristle bundles may beflattened or brought into contact with a portion of the magazine, orboth. A portion of the bristle bundles may be skewed with respect to oneanother in the magazine or may lie in intersecting planes. The steps ofadjusting and trimming may be repeated, and the step of end-rounding maybe performed in several steps. Following the steps of heating andmelting the ends of the bristle bundles, a diameter of the melted endsof the bristle bundles may be greater than the diameter of the unmeltedportion of the bristle bundles. The step of adjusting may be performedprior or subsequent to the step of end-rounding.

[0018] In another aspect, the invention is an apparatus for injectionmolding a plastic article having at least two components. The apparatuscomprises a first and a second injection molding machine each of whichcomprises at least a first injection unit. The apparatus can be operatedin one of two modes. The first mode comprises injection molding a firstcomponent of the plastic article at the first injection unit on thefirst injection molding machine and injection molding a second componentof the plastic article at the first injection unit on the secondinjection molding machine. The second mode comprises injection molding afirst component of the plastic article at the first injection unit onthe first injection molding machine or the second injection moldingmachine and injection molding a second component of the plastic articleat a second injection unit on the injection molding machine at which thefirst component was injected. The first component may comprisepolypropylene, cellulose propionate acetate, polyethylene terephthalate,or a thermoplastic polymer. The second component may comprise athermoplastic polymer or a thermoplastic elastomer. The apparatus maycomprise first, second, and third injection molding machines. If theapparatus includes a third injection molding machine, the firstcomponent may be injection molded in either of the first or secondinjection molding machines in the first mode.

[0019] The apparatus may further include a conveyer system whichdelivers a holder comprising part of the mold cavity to the injectionunit at which the first component is injected and which delivers theholder and the first component of the plastic article to the injectionunit at which the second component is injection molded. The apparatusmay further include a computer which chooses to which injection unit tosend the holder for the first injection molding step and the secondinjection molding step. At least one of the injection molding machinesmay comprise first, second, third, and fourth injection units. The firstand second injection units may be operated together and the third andfourth injection units may be operated together.

[0020] In another aspect, the invention is an apparatus for producing abrush by injection molding. The apparatus includes at least one stationat which bristle bundles are fed into channels in a magazine, a stationwhere at the relative heights of the bristle bundles in the magazine areadjusted, a station at which non-use ends of the bristle bundles aretrimmed in a level plane, a station at which non-use ends of the bristlebundles are fused, a station at which the use-ends of the bristlebundles are end-rounded, a first injection unit, and a conveyer whichtransports the magazines to the different stations. At least a portionof the magazine forms part of a mold cavity in the first injection unit.The level plane may be defined by a trim plate in cooperation with themagazine. The apparatus may further comprise a return conveyer to returnthe trim plate to an unfilled magazine. The bristle bundles may be fedinto the magazine from an endless supply, for example, a creel system,or from a pre-cut supply of bristles.

[0021] The relative heights of the bristle bundles may be adjusted bypins entering the magazine from a first and a second side. The magazineneed not be perpendicular to the pins, and an end surface of a portionof the pins need not be perpendicular to their longitudinal axis. Thestation at which the relative heights of the bristles are adjusted mayinclude an insert having holes in an arrangement corresponding to theconfiguration of the bristle bundles in the magazine, wherein the insertis placed in contact with the magazine such that the channels areco-axially aligned with the holes, and a source of pressurized airconfigured to be in fluidic communication with the channels such thatthe bristle bundles are interposed between the source of pressurized airand the holes. Each hole ends in a surface corresponding to a desiredarrangement of bristle strands or the inverse of the desired arrangementof bristle strands. The relative heights of the individual bristleswithin the bristle bundles may be adjusted at the station at which therelative heights of the bristle bundles are adjusted. Some of thebristle bundles may be skewed with respect to one another or lie inintersecting planes. The apparatus may comprise at least two stations atwhich bristle bundle heights are adjusted and two stations where at thebristle bundles are trimmed. If so, then the height adjustment stationsand trimming stations alternate such that at least some of the bristlebundles are trimmed before the magazine enters the second heightadjustment station.

[0022] The apparatus may further comprise a station at which the fusedends of the bristle bundles are flattened or pressed against a portionof the magazine. The apparatus may include a plurality of injectionunits configured such that the brush is produced from at least twodifferent polymers. The apparatus may comprise a plurality of injectionmolding machines, each of which may include a plurality of injectionunits. The injection molding machines may be configured such that thebrush is produced from at least two different polymers.

[0023] The apparatus may further comprise a packaging system for thecompleted brush or a station at which the brush can be ornamented orlabeled. The apparatus may also include a return conveyer for the usedmagazine or stations at which the relative heights of the bristlebundles are adjusted prior to or subsequent to the end-rounding station.

BRIEF DESCRIPTION OF THE DRAWING

[0024] The invention is described with reference to the several figuresof the drawing, in which,

[0025]FIG. 1 is a flow chart of the in-mold bristling process;

[0026]FIG. 2 is a plan view of a magazine which can hold up to fourtoothbrushes at a time, in which trim plates have been fitted to themagazine;

[0027]FIG. 3 is a cross-sectional view of the magazine;

[0028]FIG. 4 depicts one unit of the magazine shown in FIG. 2 withbristle bundles inserted into the channels;

[0029]FIG. 5 is a cross-sectional view of a toothbrush;

[0030]FIG. 6 is a top view of a toothbrush head with the bristle bundlesin varying orientations;

[0031]FIG. 7 depicts one unit of the magazine of FIG. 2, wherein theends of the bristle bundles have been fused;

[0032]FIG. 8A is a plan view of a mold cavity portion of the magazine,showing a slotted sleeve projecting from the molding surface and thefused end of the bristle bundle pushed onto the sleeve;

[0033]FIG. 8B is a cross-sectional view of the magazine portion of themold cavity portion depicted in FIG. 8A, showing the relativepositioning of the fuse, bristle bundle, and slotted sleeve;

[0034]FIG. 8C is a plan view of the slotted sleeve projecting from thesurface of the mold cavity portion in the magazine;

[0035]FIG. 9 is a diagram of the different possible heights of thebristle bundles and the bristles within the bundles; and

[0036]FIG. 10A is a plan view of a toothbrush head;

[0037]FIG. 10B is a cross-sectional view of a toothbrush head;

[0038]FIGS. 11A and 11B are flow charts of injection molding processesaccording to the invention;

[0039]FIG. 12A is a cross-sectional view of the magazine and a partiallycompleted toothbrush; and

[0040]FIG. 12B is a cross-sectional view of the magazine and a completedtoothbrush.

DETAILED DESCRIPTION

[0041]FIG. 1 is a flow chart showing a summary of an in-mold bristlingsystem 5 according to one embodiment of the invention. The systemincludes a nylon preparation subsystem 10, an injection moldingsubsystem 20, and a conveying and packaging subsystem 30. Thetoothbrushes are carried through the system 5 by a magazine 100 (FIG.2), which includes a section of the mold and retaining means for bristlebundles. The magazine can hold bristles for any number of toothbrushes;the embodiment of the magazine shown in FIG. 2 is adapted for productionof up to four toothbrushes. Because the bristle bundles for eachtoothbrush are supported by an individual clamp mechanism, the apparatusof the invention can be operated with magazines that hold any number oftoothbrushes from one to six, seven, eight, or even more. The clampincludes a sliding switch 112 which moves a sliding cam action 114 in abrush holding unit 121. FIG. 3 shows a cross section of the magazine100, including a locking plate 116, which is shown projecting from themagazine 100. The sliding cam action 114 shifts locking plate 116between an engaged and a disengaged position when moved by slidingswitch 112. The locking plate 116 includes holes which, when the lockingplate 116 is in a disengaged position, coincide with channels 118 whichrun through the magazine. Bristle bundles 130 are inserted into channels118 from an endless supply, for example, a creel system, and cut at cutplate 120 of magazine 100. In an alternative embodiment, the bristlesmay be inserted into channel 118 from hanks or other arrangements ofpre-cut bristles. In addition to the bristles, an insert such as a metalshank, plastic insert, or other non-bristle object may be inserted intothe magazine and incorporated into the brush. The bristle bundlespenetrate through the channels 118 into channels 122 in trim plate 124,which cooperates with a mold cavity portion 126 cut into a mold side 128of magazine 100 in the magazine. Channels 122 coincide with the channels118 through the magazine 100. When locking plate 116 is engaged, theholes in the plate are off-set from channels 118 and clamp the bristlebundles 130 in place. The locking plate 116 can be disengaged andre-engaged to allow the bristle bundles 130 to be moved within thechannels 118 or released from the magazine 100 depicted in FIG. 2.Because each brush holding unit 121, depicted in part by switch 112 andlocking plate 116, has an individual clamping mechanism, the bristlebundles can be inserted and manipulated for each brush individually.

[0042]FIG. 4 shows the bristle bundles 130 inserted into the channels118 in one brush holding unit 121 of magazine 100. According to apreferred embodiment of the invention, the bristle bundles 120 areinserted into the magazine 100 at two bristle inserting stations in thenylon preparation unit 10. Bristle bundles 130 are inserted into two ofthe four brush holding units 121 at one of the stations and intochannels 118 of the remaining bristle holding units 121 at the secondbristle inserting station. Before the magazine 100 travels from thefirst bristle inserting station to the second bristle inserting station,the bristle bundles 130 for the first two bristle holding units 121 arecut. The bristle bundles 130 for the second two bristle holding units121 are cut at the second bristle inserting station. While FIG. 2 showsthe cut plate 120 as a component of magazine 100, the cut plate mayinstead be incorporated into a feed guide through which the bristlebundles are initially introduced into the apparatus.

[0043] Once the bristle bundles 130 have been inserted into the magazine100 and cut from the endless strand, they are shaped and profiled. Pinsapproach both ends of the cut bundles 130 through channels 118 and 122and push against the bundles 130, adjusting both the relative bundleheight and the surface profile. The pins need not be flat. Eachindividual bristle bundle 130 can have a profile, and overall shape ofthe collective of bristle bundles 130 may also be contoured. Forexample, the overall collection of bristle bundles 130 may have a roundprofile, as shown in FIG. 5. To maintain the profile depicted in FIG. 5,each individual bristle bundle 130 cannot have its ends in a planeparallel to the magazine. Instead, each individual bristle bundle 130has a contour which conforms to the overall contour of the bristlebundles 130. Of course, the final profile of the brush may be a flatplane.

[0044] In an alternative embodiment, the bristle bundles may be profiledwith compressed air. Methods for air profiling are well known in theart; one method is disclosed in U.S. Pat. No. 5,454,626 to Schiffer, etal., the contents of which are incorporated herein by reference. A plateis brought in contact with a surface of the magazine. If the plate isbrought in contact with the back-side of the magazine 100, into whichthe use ends of the bristle bundles 130 protrude, then the plate willhave holes whose ends are machined to reflect the final profile of thebristles. Pressurized air is directed into the channels 118 and 122,pushing the bristle bundles 130 against the inside of the plate andprofiling them. The procedure can be performed in the same manner with aplate abutting the mold cavity side of the magazine 100. In this case,the ends of the holes in the plate are machined to have the reverse ofthe profile desired for the bristle bundles, and pressurized air isdirected into the channels 118 from the back-side of magazine 100.

[0045] Indeed, while FIG. 3 shows a series of channels 118 which are allparallel to one another, it is not necessary that the channels 118, 122or the bristle bundles 130 be so oriented. Individual channels 118, 122and bristle bundles 130 may be skewed with respect to one another or maylie in intersecting planes.

[0046] For example, FIG. 6 shows a diagram of a brush head 200,including several orientations of bristle bundles 130. The center row ofbristle bundles 210 is oriented roughly perpendicularly to the head ofthe brush. A second group of bristle bundles 212 is situated in a planeparallel to the bristle bundles 210 but in a skewed orientation. Thatis, the bristle bundles in rows 210 and 212 lie in parallel planes, butthe individual bundles in the two groups are not parallel to each other.Third and fourth groups of bristle bundles 214 and 216 lie in planeswhich intersect not only each other but the planes defined by bristlebundle groups 212 and 210. In general, the bristle bundles 130 can besituated at any orientation with respect to the head 200 of the brush.From the above discussion, it is evident that the invention can be usedto produce brushes having a wide variety of bristle bundle sizes,shapes, and arrangements. For example, currently marketed brushesfrequently include triangular and elliptical bristle bundles, and thefigures depict several different arrangements of bristles.

[0047] Depending on the relative orientations of the bristle bundles 130with respect to each other, several profiling station/trimming stationpairs may be necessary. At each station, the magazine may need to berotated or tilted, depending on the necessary orientation of the pinswith respect to the magazine. Alternatively, the profiling and trimmingstations may be oriented relative to the magazine 100. For example, forthe brush head 200, separate profiling stations are required for bundlesets 214 and 216.

[0048] While the bristle bundles are oriented at a variety of angles inmagazine 100, they are parallel to one another as they enter a feedsystem which directs the bristle bundles 130 into the magazine 100.Thus, the bristle bundles must traverse a corner to pass from the feedsystem into the magazine. If the angle of the bristle bundles withrespect to the face of the magazine 100 is too large, the bristle bundlemay jam as it is being fed into the magazine. Thus, it is preferable toinclude a series of transition plates between the feed system and themagazine. An exemplary design for the transition plates is included inour concurrently filed application entitled, “Method of BristleInsertion for Brush Production,” the contents of which are incorporatedherein by reference. The transition plates may be mounted to and formpart of the feed system. Each plate includes channels which togetherform a continuous path for the bristle bundle material through the setof plates, much as channels 118 and 122 describe a continuous paththrough magazine 100. However, in each plate, the channels are orientedat a different angle. For example, the channels in the plate closest toa bristle source may be oriented at 3°, while the next plate in the setis oriented at 6°. Upon emerging from the second set of plates, thebristle bundles will be oriented at 6° with respect to the materialentering the feed system. A series of plates can be set up consecutivelyto transition the bristle bundles over a wide variety of angles,depending on the number of plates and the included angle in each plate.

[0049] The magazine 100 then proceeds to a trimming station, whereat thebristle bundles 130 are cut from the mating side of the magazine at thetrim plate 124. As can be seen from FIG. 3, the collection of bristlebundles 130 will define a level plane as they protrude into the trimplate 124 and a profiled surface oriented towards the cut plate 120.Because the surface of the trim plate 124 is flat, the cut surface ofthe bristle bundles 130 also form a flat plane with respect to eachother. However, the surface of the trim plate 124, as shown in FIG. 2,is not necessarily flush with the surface of the magazine 100. Thus,when the trim plate 124 is removed, the ends of the bristle bundles 130are not necessarily in the same plane as the mold side 128 of themagazine 100.

[0050] The thickness of the trim plate 124, and, thus, the height atwhich it protrudes above the surface of the mating plate 128, may beadjusted depending on the properties of the bristle bundle material. Asis well known in the art, different materials will lead to differentamounts of contraction in the bristle bundles 130 when they are heatedand fused. The extent of shrinkage also depends heavily on the diameterof the bristle bundles 130 and coatings which may be present on theindividual bristle strands. Some materials may require a large excesslength and a thick trim plate 124, while others may not require anyexcess length at all, allowing the trim plate 124 to lie flush with thesurface of the magazine 100.

[0051] After the magazine 100 has proceeded to all the profile andtrimming stations, the trim plate 124 is removed from the magazine 100and returned to the beginning of the system 5 by a separate returnmechanism, such as a conveyor. The trimmed ends of the bristle bundles130, which protrude from the magazine 100 as shown in FIG. 4, are thenfused with a non-contact heater. While it is preferable to heat thebristle bundles 130 with a non-contact heater, it is well known in theart to use contact heaters, chemicals, hot air cannons, or any othertechnique which will increase flow in the polymer forming the bristles.The heat melts the ends of the bristle bundles 130, and the polymerflows to form small, melted fuseballs 220 at the end of the bristlebundles 130, as shown in FIG. 7.

[0052] The fuses 220 may be pressed against the inside of the moldcavity portion 126. If they are still hot and malleable, they may alsobe flattened into a desired shape. The fuses 220 are not actually pushedagainst the inside surface of the mold cavity portion 126. Instead, theyare pushed against small slotted sleeves 230 which protrude from theopenings of the individual channels 118 (FIG. 8). FIG. 8A shows theslotted sleeves 230 protruding from the surface of mold cavity portion126. Fuse 220 has been pushed against the top surface of the sleeve.FIG. 8B shows a cross section of the view in FIG. 8A, wherein thechannels 118 and bristle bundles 130 are visible. An individual slottedsleeve 230 on an empty magazine 100 is shown in FIG. 8C. The sleeves 230each have small slots 232. The purpose of these slots 232 and thesleeves 230 will be explained in connection with the injection moldingsystem.

[0053] After the bristle bundles 130 have been fused and the fused ends220 optionally flattened and pushed against the slotted sleeves 230within the mold cavity portion 126, the other, unmelted, ends of thebristle bundles 130 are end-rounded. These ends will become the use endsof the brush; therefore, they must be processed in order to avoidcutting or overly abrading the gums of the user. Sanders rotating in acircular motion abrade the end of the bristles, rounding the sharpcorners of the cut ends. FIG. 9 shows a number of exemplary heights andprofiles for the bristle bundles 130. Any combination of these or otherprofiles may be used in a toothbrush, according to the desires of themanufacturer. If the maximum difference x in height among the bristlebundles 130 is less than 3.2 mm, the ends of the bristles can all be endrounded in a single step. Otherwise, it may be necessary to end-roundthe bristles in two or more steps at two or more stations. At one of thestations, some of the bristles are protected with an insert whichprevents them from being overly abraded. Preferably, the longer bristlesare shielded during the end rounding of the shorter bristles. In thiscase, the distance between the bristle ends and the sander is adjustedsuch that, when the longer bristles are sanded, the shorter bristles donot touch the sander. The use of such inserts is well known to thoseskilled in the art.

[0054] The processed bristles, still clamped into the magazine, are thentransported to a mold. A preferred embodiment of the system 5 includesthree injection mold machines, each having an input queue, fourinjection units, and an output conveyor. In a preferred embodiment, eachinjection unit can supply material for two mold cavities. The injectionmold machines can be configured to produce brushes having monochromaticor multicolored handles. However, the invention does not require twelveinjection units; it can be practiced with four injection units which maybe located on a single injection machine. Alternatively, as will be seenbelow, it is possible to practice the invention using two injection moldmachines, each of which includes either two or four injection units. Inany one of the above embodiments, additional injection mold machines,which may in turn include two or more injection units, may be added tothe system as required. In a preferred embodiment, each injection unitcan inject materials for two brush holding units 121 on the magazine 100at the same time. The handle of brush 240 (see FIG. 12) is formed in twoinjection shots, and the operator may choose whether to perform bothinjections on a single injection mold machine or whether to do the firstinjection on one machine and the second injection on a second machine.In addition, because each of the twelve injection units can be set upwith different colors of the polymer, toothbrushes can be produced in avariety of colors simultaneously. Of course, if only a single color isdesired for the handle, only two injection units are necessary for thisembodiment. Indeed, depending on the number of components or the numberof brush holding units 121 on the magazine 100, it may be desirable toconfigure the injection unit to supply fewer or more mold cavities or touse fewer or more injection units on a given machine. Alternatively, thehandle can be formed in a plurality of injection molding shots toproduce a brush with three, four, or more components. Indeed, it is noteven necessary to injection mold the entire head of the brush in thefirst shot. It will be clear from discussion of the various operatingmodes that additional injection machines can be added to the system,regardless of how many colors or components the final product will have.Additionally, the handle can be compression molded instead of injectionmolded. In general, the invention is meant to encompass any number ofinjection mold machines with any number of injection units which in turnmay each supply any number of mold cavities. The number andconfiguration of mold machines and units will be determined by thedesign of the brush and the capacity of the magazine.

[0055] In general, for the first injection molding shot, the mold cavityportions 126 are mated with complementary mold cavity portions in thefirst injection mold machine. As noted before, mold cavity portion 126forms part of the head 200 of the brush 240. The mold cavity portions inthe machine, in combination with mold cavity portion 126, define theremainder of brush handle section 250. In a preferred embodiment, thefour mold cavities defined by the mating of the portions on the magazineand the machine are supplied by two injection units. Indexing mechanismssuch as pins and grooves are used to carefully align the mold cavityportions 126 in magazine 100 with the mold cavity portions in theinjection mold machine. The first injection molding shot is typicallypolypropylene, cellulose acetate propionate (propionate), orpolyethylene terephthalate. Other thermoplastics can also be used topractice the invention. Following the first shot, the injection moldmachine opens, and the magazine transports the bristle bundles 130 andthe newly formed brush handle section 250 to second shot mold with apick-and-place system or other transport mechanism (FIG. 12A). In apreferred embodiment, the second shot mold includes four mold cavityportions fitted with two additional injection units. It is necessary toensure that the first section 250 of the brush handle is sufficientlycool and stiff not to sag under its own weight because its center ofgravity is not supported by the mold cavity portion 126 in the magazine100. After the transfer, the magazine 100 is again carefully alignedwith the second set of mold cavity portions. This time, the brush handlesection 250 itself actually forms a boundary for the molding of thesecond component 252. The second polymer, typically a thermoplasticelastomer, is then injection molded. When the injection mold machineopens, the entire brush 240 is fully formed and supported by the bristlebundles 130 clamped in the magazine 100. Modules to stamp decorations,paste labels, or otherwise ornament the brushes 240 may be added to thesystem 5 following the mold units and prior to the release of thebrushes 240. It is common to hot stamp an inventory label, such as adate stamp, onto the handles as well. Techniques for ornamenting andlabeling brushes are well known in the art. Once brush 240 has beendecorated, it is transported to a packaging subsystem 30 and releasedfrom the magazine 100. The magazine 100 is returned to the beginning ofthe production system 5 on a return conveyor, and the completed brushes240 are packaged for transport to the customer. A wide variety ofappropriate packaging methods for the invention are well known in theart. For example, brushes can be bulk packed into cartons or placed inindividual boxes. An RF sealer may be employed to enclose the brushes inindividual blister packs. Additional objects, such as small toys ornovelty items, can be co-packaged with the brushes if a form-fill-sealapparatus is used. A flat sheet of plastic is configured to hold thebrush and optional toy, which are then loaded into the newly formedpockets in the plastic sheet. A backer, such as a piece of cardboard, isthermally sealed to the plastic, enclosing the brush and other items.

[0056] One goal of prior art in-mold bristling techniques is to solvetwo problems relating to the injection molding of incompletely sealedsystems: 1) the release of air from the mold and 2) the prevention offlashing of injection molded material into the face of brush 240. Theinstant invention is unique in being able to solve these two problemssimultaneously. The slot 232 in the sleeve 230 allows air to be pushedout of the mold cavity portion 126 through the channels 118 by thepressure of the injection molded material. However, the slot 232 in thesleeve 230 also allows a small amount of injection molded material toexit the cavity. This injection molded material forms small tabs 242 inthe bristle bundles 130 which further helps retain them in the head 200of the brush 240 (FIG. 10A, bristle bundle 130 shown as outline). FIG.10B depicts a cross-sectional view of fuse 220 and bristle bundle 130across tabs 242. For current bristle materials, the fused ends 220 ofthe bristle bundles 130 are somewhat larger in diameter than the bristlebundles 130. This also facilitates retention because injection moldedmaterial flows around the fuses 220 and the narrower bristle bundles130, obstructing the path of the fused ends 220 through the head 200 ofthe brush 240. The tabs 242, meanwhile, are large enough to retain thebristle bundles 130 within the brush head 200, but not so large as toappear unsightly to the consumer.

[0057] As noted above, the molding subsystem 20 of the production system5 may be operated in two modes. In the first mode, the magazine 100transports the bristle bundles 130 to a first shot mold in any of thethree injection molding machines at which the first component of thetoothbrush handle is injection molded (FIGS. 11A and 12A). The magazine100, carrying a first injection molded section 250 of the brush handle,is then transported to a second shot mold in the same injection moldmachine, and a second section 252 of the brush 240 is injection molded(FIG. 12B). The output conveyor takes the magazine 100 to the systemconveyor, which transports the magazine 100 directly to any intermediatedecorating units and then to the packaging subsystem system 30. Acomputer notes the occupancy of the injection mold machines and directsincoming magazines 100 accordingly to prevent backlogs and congestionand to optimally utilize the mold machines.

[0058] In a second mode, depicted in FIG. 11B, the first two injectionmold machines are used to inject the first component 250, and the thirdinjection molding machine is used to inject the second component 252.For the embodiment where a magazine carries four brushes and eachinjection unit supplies two molds, the computer directs an incomingmagazine 100 to either a first or second pair of injection units oneither of the first two injection mold machines, depending on theiroccupancy. After the first component 250 is injected, the magazine 100,carrying the first section 250 of the brush handle, is then directed toone of two second shot molds on the third injection mold machine, eachof which, in this embodiment, comprises two injection units. The fourpairs of injection units on the first two machines can support two pairsof injection units on the third machine because, for some materials, itwill take somewhat longer to injection mold the first component 250 ofthe handle and allow it enough time to cool so that it does not bend orflex as it is being carried to the third injection mold machine at whichthe second component 252 is injection molded. As noted above, it may bedesirable to configure the injection mold machines to support fewer orgreater molds for the first and/or second shot. Again, a computer can beused to direct the incoming magazines among the mold machines. Both ofthese modes can be adjusted to allow production of brushes with fewer ormore components.

[0059] The machining of the mold cavity portion 126 of the magazine 100,in addition to the mold cavity portions in the injection mold machines,must be carefully controlled to ensure that the mold cavity portion 126in the magazine 100 correctly mates with the mold cavity portion for thefirst injection mold shot and that the first component of the brushhandle correctly mates with the mold cavity portion for the secondinjection mold shot. Careful machining is required to account for thethermal expansion, or, in this case, contraction of the first injectionmolded component 250. The first component 250 of the brush handle willoccupy a slightly larger volume in the first injection unit than it doesin the second injection unit because the plastic will shrink as itcools. The amount of shrinkage varies with the polymer that is used toform the handle; thus, the machining must be carefully adjusted for thedifferent polymers that might be used to form the first component of thebrush. Different plastics may shrink {fraction (3/1000)}″ to {fraction(25/1000)}″ per inch as they cool from the molding temperature to atemperature where the handles can be removed from the mold. In addition,different plastics will require different cooling times and differentinjection molding times, partially dictating which one of the twooperation modes a practitioner will use when injection molding thebrushes. As will be evident to one skilled in the art, it is possible toend-round the bristles of the brush after the handle has been injectionmolded.

[0060] Other embodiments of the invention will be apparent to thoseskilled in the art from a consideration of the specification or practiceof the invention disclosed herein. It is intended that the specificationand examples be considered as exemplary only, with the true scope andspirit of the invention being indicated by the following claims.

What is claimed is:
 1. A process for manufacturing brushes, comprising:inserting a plurality of bristle bundles into a first mold cavityportion in a magazine; manipulating at least one end of the bristlebundles; mating the first mold cavity portion with a second mold cavityportion in an injection mold; and injection molding at least a portionof a brush handle, wherein the first and second cavity portions definethe shape of the portion of the brush handle.
 2. The process of claim 1,wherein the bristles are inserted into the magazine from an endlesssupply.
 3. The process of claim 1, wherein the bristles are insertedinto the magazine from a supply of pre-cut bristles.
 4. The process ofclaim 1, wherein the step of manipulating comprises adjusting therelative heights of the bristle bundles with respect to one anotherbefore the first portion of the brush handle is injection molded.
 5. Theprocess of claim 4, wherein the step of adjusting comprises adjustingthe relative heights of at least a portion of the bristles within thebundles with respect to each other.
 6. The process of claim 4, furthercomprising trimming a non-use side of the bristle bundles to produce alevel plane.
 7. The process of claim 4, further comprising end-roundingat least a portion of the bristle bundles.
 8. The process of claim 7,further comprising adjusting the relative height of the bristle bundleswith respect to one another such that the profile of the bristle bundlesis inverted with respect to the profile they had following the prioradjusting step.
 9. The process of claim 1, wherein the step ofmanipulating comprises end-rounding at least a portion of the bristlebundles.
 10. The process of claim 9, wherein the step of end-rounding isperformed following the step of injection molding.
 11. The process ofclaim 1, wherein the step of manipulating comprises fusing a non-use endof each bristle bundle to form regions on each bristle bundle having agreater diameter than that of the remainder of the bristle bundle. 12.The process of claim 11, further comprising pressing the fused endsagainst a portion of the first mold cavity portion.
 13. The process ofclaim 11, wherein the fusion is accomplished thermally or chemically.14. The process of claim 13, wherein the non-use ends of the bristlebundles are fused by a contact heater, a non-contact heater, or hot air.15. The process of claim 13, wherein the fusion is accomplishedthermally, and wherein the process further comprises at least partiallyflattening the heated, melted ends of the bristle bundles while they arestill warm.
 16. The process of claim 1, wherein at least a portion ofthe brush handle comprises polypropylene, cellulose propionate acetate,polyethylene terephthalate, or a thermoplastic polymer.
 17. The processof claim 1, further comprising: removing the completed portion of thebrush handle from the second mold cavity portion; mating the magazineand the portion of the brush handle with a subsequent mold cavityportion; and injection molding an additional portion of the brushhandle, wherein the completed portion of the brush handle and thesubsequent mold cavity portion define the shape of the additionalportion of the brush handle.
 18. The process of claim 17, wherein theadditional portion of the brush handle comprises a thermoplasticelastomer, polypropylene, cellulose propionate acetate, polyethyleneterephthalate, or a thermoplastic polymer.
 19. The process of claim 17,wherein the steps of removing, mating, and injection molding arerepeated.
 20. The process of claim 17, wherein the completed portion ofthe brush handle is at least partially supported by the bristle bundleswhen it is carried by the magazine to the subsequent mold cavityportion.
 21. The process of claim 1, wherein at least a portion of thebristle bundles are not retained in the completed portion of the brush.22. The process of claim 1, further comprising packaging the completedbrushes.
 23. The process of claim 1, wherein the magazine is arrangedand constructed to hold bristle bundles corresponding to a plurality ofbrushes simultaneously and wherein the plurality of brushes can beproduced simultaneously.
 24. The process of claim 23, wherein at least aportion of the plurality of brushes are not all the same color.
 25. Theprocess of claim 23, wherein the magazine is arranged and constructed tohold bristle bundles corresponding to four brushes simultaneously. 26.The process of claim 1, further comprising ornamenting the completedbrush.
 27. The process of claim 1, wherein ornamenting compriseshot-stamping, stamping a decoration, or pasting a label.
 28. The processof claim 1, further comprising labeling the completed brush.
 29. Theprocess of claim 1, further comprising placing an insert into themagazine.
 30. The process of claim 29, wherein the insert is a metalshank or a plastic insert.
 31. A magazine for conveying bristle bundlesalong a brush making apparatus comprising: a mold face; a mold cavityportion disposed in the mold face having the shape of part of a head ofa brush; a back side; a clamping plate disposed between the mold faceand the back side; and a plurality of channels extending through themagazine into the mold cavity for holding bristle bundles in aconfiguration corresponding to the desired arrangement of a set ofbristle bundles in the brush.
 32. The magazine of claim 31, wherein themagazine can hold sets of bristle bundles for a plurality of brushes,and the magazine is arranged and constructed to clamp and release theset of bristle bundles for each brush independently.
 33. The magazine ofclaim 32, wherein the magazine is arranged and constructed to hold atleast four sets of bristle bundles.
 34. The magazine of claim 31,wherein each channel comprises an opening into the mold cavity portionhaving a slotted sleeve.
 35. The magazine of claim 31, furthercomprising a detachable trim plate in cooperation with the mold cavityportion, wherein the trim plate includes channels which coincide withthe channels through the magazine.
 36. The magazine of claim 35,wherein, when the trim plate is in cooperation with the mold cavityportion, a surface of the trim plate is flush with the mold face of themagazine.
 37. The magazine of claim 35, wherein, when the trim plate isin cooperation with the mold cavity portion, the trim plate projectsabove the mold face.
 38. The magazine of claim 31, wherein, when themagazine is seated in an injection molding apparatus, the mold cavityportion of the magazine cooperates with a mold cavity portion of theapparatus to define a mold cavity having the shape of a portion of thebrush.
 39. The magazine of claim 31, wherein a portion of the channelsare skewed with respect to one another.
 40. The magazine of claim 31,wherein a portion of the channels lie in intersecting planes.
 41. Themagazine of claim 31, further comprising a cut plate mounted on the backside of the magazine having channels coinciding with the channelsthrough the magazine.
 42. A method for processing bristles for a brush,comprising: holding the bristles in bundles in a magazine; adjusting therelative height of at least a portion of the bristle bundles withrespect to each other; trimming non-use ends of at least a portion ofthe bristle bundles to produce a level plane; heating the non-use endsof the bristle bundles to melt the ends of the bristles; andend-rounding use ends of the bristle bundles.
 43. The method of claim42, wherein the step of adjusting is performed with pins which approachboth ends of the bristle bundles.
 44. The method of claim 42, whereinthe step of adjusting comprises: providing a plate in cooperation with aside of the magazine, wherein the plate includes holes in an arrangementcorresponding to a configuration of the bristles in the magazine andwherein each hole ends in a surface corresponding to a desiredarrangement of bristle strands or the inverse of the desired arrangementof bristle strands; and pressing an end of the bristle bundles againstthe surface in the hole with a pressurized fluid.
 45. The method ofclaim 42, wherein the step of adjusting comprises adjusting the relativeheights of at least a portion of the bristles within the bundles withrespect to each other.
 46. The method of claim 42, wherein after thestep of heating and melting the non-use ends of the bristle bundles, themelted portion of the bristle bundles are flattened.
 47. The method ofclaim 42, wherein after the step of heating and melting the non-use endsof the bristle bundles, the melted ends of the bristle bundles arebrought into contact with a portion of the magazine.
 48. The method ofclaim 42, wherein a portion of the bristle bundles are skewed withrespect to each other in the holder.
 49. The method of claim 48, whereinthe steps of adjusting and trimming are repeated at least once.
 50. Themethod of claim 42, wherein a portion of the bristle bundles lie inintersecting planes.
 51. The method of claim 50, wherein the steps ofadjusting and trimming are repeated at least once.
 52. The method ofclaim 42, wherein the step of end-rounding is performed in severalsteps.
 53. The method of claim 42, wherein, following the step ofheating and melting the ends of the bristle bundles, a diameter of themelted ends of the bristle bundles is greater than the diameter of theunmelted portion of the bristle bundles.
 54. The method of claim 42,wherein the step of adjusting is performed prior or subsequent to thestep of end-rounding.
 55. An apparatus for injection molding a plasticarticle having at least two components, comprising: at least a first anda second injection molding machine, wherein each injection moldingmachine comprises at least a first injection unit, and the apparatus canbe operated in either a first mode or a second mode, wherein: the firstmode comprises: injection molding a first component of the plasticarticle at the first injection unit on the first injection moldingmachine; and injection molding a second component of the plastic articleat the first injection unit on the second injection molding machine, andthe second mode comprises: injection molding a first component of theplastic article at the first injection unit on the first injectionmolding machine or the second injection molding machine; and injectionmolding a second component of the plastic article at a second injectionunit on the injection molding machine whereat the first component wasinjected.
 56. The apparatus of claim 55, wherein the first componentcomprises polypropylene, cellulose propionate acetate, polyethyleneterephthalate, or a thermoplastic polymer.
 57. The apparatus of claim55, wherein the second component comprises a thermoplastic polymer or athermoplastic elastomer.
 58. The apparatus of claim 55, wherein theapparatus comprises first, second, and third injection molding machines.59. The apparatus of claim 58, wherein in the first mode, the firstcomponent may be injection molded in either of the first or secondinjection molding machines.
 60. The apparatus of claim 55, furthercomprising a conveyor system which delivers a holder comprising a partof the mold cavity to the injection unit at which the first component isinjected and which delivers the holder and the first component of theplastic article to the injection unit at which the second component isinjection molded.
 61. The apparatus of claim 60, further including acomputer which chooses to which injection unit to send the holder forthe first injection molding step and the second injection molding step.62. The apparatus of claim 55, wherein at least one of the injectionmold machines comprises first, second, third, and fourth injectionunits.
 63. The apparatus of claim 62, wherein the first and secondinjection units are operated together and wherein the third and fourthinjection units are operated together.
 64. An apparatus for producing abrush by injection molding, comprising: at least one station whereatbristle bundles are fed into channels in a magazine; at least onestation whereat the relative heights of the bristle bundles in themagazine are adjusted; at least one station whereat the non-use ends ofthe bristle bundles are trimmed in a level plane; at least one stationwhereat the non-use ends of the bristle bundles are fused; at least onestation whereat the use ends of the bristle bundles are end-rounded; atleast a first injection unit; and a conveyor which transports themagazine to the different stations, wherein at least a portion of themagazine forms part of a mold cavity in the first injection unit. 65.The apparatus of claim 64, wherein the level plane is defined by a trimplate in cooperation with the magazine.
 66. The apparatus of claim 65,further comprising a return conveyor to return the trim plate to anunfilled magazine.
 67. The apparatus of claim 64, wherein the bristlebundles are fed into the magazine from an endless supply.
 68. Theapparatus of claim 67, wherein the endless supply comprises a creelsystem.
 69. The apparatus of claim 64, wherein the bristle bundles arefed into the magazine from a pre-cut supply of bristles.
 70. Theapparatus of claim 64, wherein the relative heights of the bristlebundles are adjusted by pins entering the magazine from a first side anda second side.
 71. The apparatus of claim 70, wherein the magazine isnot perpendicular to the pins.
 72. The apparatus of claim 70, wherein anend surface of-at least a portion of the pins is not perpendicular to alongitudinal axis of said pins.
 73. The apparatus of claim 64, whereinthe station whereat the relative heights of the bristle are adjustedcomprises: an insert comprising holes in an arrangement corresponding tothe configuration of the bristle bundles in the magazine, wherein eachhole ends in a surface corresponding to a desired arrangement of bristlestrands or the inverse of the desired arrangement of bristle strands;placing means to bring the insert into contact with the magazine suchthat the channels are coaxially aligned with the holes; and a source ofpressurized air configured to be in fluidic communication with thechannels such that the bristle bundles are interposed between the sourceof pressurized air and the holes.
 74. The apparatus of claim 64, whereinthe relative heights of the individual bristles within the bristlebundles are adjusted at the station whereat the relative heights of thebristle bundles are adjusted.
 75. The apparatus of claim 64, whereinsome of the bristle bundles are skewed with respect to each other. 76.The apparatus of claim 64, wherein some of the bristle bundles lie inintersecting planes.
 77. The apparatus of claim 64, comprising at leasttwo stations whereat bristle bundle heights are adjusted and twostations whereat the bristle bundles are trimmed, wherein the heightadjustment stations and trimming stations alternate, such that at leastsome of the bristle bundles are trimmed before the magazine enters thesecond height adjustment station.
 78. The apparatus of claim 64, furthercomprising a station whereat the fused ends of the bristle bundles arepressed against a portion of the magazine.
 79. The apparatus of claim64, further comprising a station whereat the fused ends of the bristlebundles are flattened.
 80. The apparatus of claim 64, wherein theapparatus includes a plurality of injection units and wherein theplurality of injection units are configured such that the brush isproduced from at least two different polymers.
 81. The apparatus ofclaim 64, further comprising a plurality of injection molding machines.82. The apparatus of claim 81, wherein each injection molding machineincludes a plurality of injection units.
 83. The apparatus of claim 81,wherein the injection molding machines are configured such that thebrush is produced from at least two different polymers.
 84. Theapparatus of claim 64, further comprising a packaging system for thecompleted brush.
 85. The apparatus of claim 64, further comprising areturn conveyor for the used magazine.
 86. The apparatus of claim 64,further comprising a station whereat the brush can be ornamented orlabeled.
 87. The apparatus of claim 64, further comprising stationswhereat the relative heights of the bristle bundles are adjusted priorto or subsequent to the end-rounding station.